Unless you intend to wire the lights in yourself, this wiring harness is highly recommended for those purchasing any of Street Scene's 05+ Mustang V6 to GT Conversion Grille or Center Mount Cobra-style Conversion Grille kits. This harness properly powers the OEM factory GT Driving Lights while protecting the Mustang Smart Box, and includes a round OEM-style switch, in-line fuse, power relay and factory-style plugs. The length of the harness wiring accomodates both the GT-style (wide-spread) or Cobra-style (center-mount) positioning of the driving lights. Requires OEM factory GT driving lights which are reasonably priced and readily available through your local Ford dealer.